A discontinuous Galerkin method for seismic soil–structure interaction analysis in the time domain     

Si‐Hwan Park  Nicolas Antin 《地震工程与结构动力学》2004,33(2):285-293

A technique for modeling transient wave propagation in unbounded media is extended and applied to seismic soil–structure interaction analysis in the time domain. The technique, based on the discontinuous Galerkin method, requires lower computational cost and less storage than the boundary element method, and the time‐stepping scheme resulting from Newmark's method in conjunction with the technique is unconditionally stable, allowing for efficient and robust time‐domain computations. To extend the technique to cases characterized by seismic excitation, the free‐field motion is used to compute effective forces, which are introduced on the boundary of the computational domain containing the structure and the soil in the vicinity of the structure. A numerical example on a dam–foundation system subjected to seismic excitation demonstrates the performance of the method. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

Aircraft Observations of the Development of Thermal Internal Boundary Layers and Scaling of the Convective Boundary Layer Over Non-Homogeneous Land Surfaces   总被引：1，自引：0，他引：1  

Michail A. Strunin  Tetsuya Hiyama  Jun Asanuma  Tetsuo Ohata 《Boundary-Layer Meteorology》2004,111(3):491-522

This study investigates the convective boundary layer (CBL) that develops over anon-homogeneous surface under different thermal and dynamic conditions. Analysesare based on data obtained from a Russian research aircraft equipped with turbulentsensors during the GAME-Siberia experiment over Yakutsk in Siberia, from April to June 2000.Mesoscale thermal internal boundary layers (MTIBLs) that radically modified CBLdevelopment were observed under unstable atmospheric conditions. It was found thatMTIBLs strongly influenced the vertical and horizontal structures of virtual potentialtemperature, specific humidity and, most notably, the vertical sensible and latent heatfluxes. MTIBLs in the vicinity of the Lena River lowlands were confirmed by clouddistributions in satellite pictures.MTIBLs spread through the entire CBL and radically modify its structure if the CBL isunstable, and strong thermal features on the underlying surface have horizontal scalesexceeding 10 km. MTIBL detection is facilitated through the use of special parameterslinking shear stress and convective motion.The turbulent structure of the CBL with and without MTIBLs was scaled usingthe mosaic or flux aggregate approach. A non-dimensional parameterL_Rau/L_hetero (where L_Rau is Raupach's length and L_hetero is the horizontal scale of the surface heterogeneity)estimates the application limit of similarity and local similarity scaling models forthe mosaic parts over the surface. Normalized vertical profiles of wind speed, airtemperature, turbulent sensible and latent heat fluxes for the mosaic parts withL_RauL_hetero < 1 could be estimated by typical scalingcurves for the homogeneous CBL. Traditional similarity scaling models for the CBLcould not be applied for the mosaic parts with L_Rau/L_hetero > 1.For some horizontally non-homogeneous CBLs, horizontal sensible heat fluxes werecomparable with the vertical fluxes. The largest horizontal sensible heat fluxes occurred at the top of the surface layer and below the top of the CBL.Formerly affiliated to the Frontier Observational Research System for Global ChangeFormerly affiliated to the Frontier Observational Research System for Global Change  相似文献   

第六届全国岩土工程实录交流会专题报告之一桩基础理论与技术若干进展与问题探讨     

吴永红  李文春  翁鹿年 《岩土工程技术》2004,18(4):163-167

介绍桩土相互作用理论若干进展和两种新桩型、新工艺后压浆灌注桩、挤扩灌注桩,并对有关问题进行探讨.  相似文献   

H-adaptivity applied to liquefiable soil in nonlinear analysis of soil–pile interaction     

Xiaowei Tang  T. Sato 《Soil Dynamics and Earthquake Engineering》2005,25(7-10):689-699

This paper is concerned with application of the h-adaptive finite element method to dynamic analysis of a pile in liquefiable soil considering large deformation. In finite element analysis of pile behavior in liquefiable soil during an earthquake, especially considering large deformation of liquefied ground, error due to discretization in the zone near the pile becomes very large. Our purpose was to refine the approximation of the finite element method. The updated Lagrangian formulation and a cyclic elasto-plastic model based on the kinematic hardening rule were adopted to deal with the nonlinearity of the soil. The mixed finite element and finite difference methods together with the u-p formulation and Biot's two-phase mixture theory were used. To improve the accuracy and increase the efficiency of finite element analysis, an h-adaptive scheme that included a posteriori error estimation and h-version mesh refinement was applied to the analysis. The calculated results of effective stress were smoothed locally by the extrapolation method and smoothed stress was used to calculate the L₂ norm of the effective stress error in the last step of the calculation of each time increment. The mesh was refined by a fission procedure based on the indication of the error estimate As a numerical example, a soil–pile interaction system loaded cyclically was analyzed by our method.  相似文献   

相山矿田低温热水及其与铀矿化关系   总被引：2，自引：0，他引：2  

邵飞 《地球科学》2005,30(2):206-210,240

从矿田现代温热水入手，运用水文地球化学、同位素水文地质等手段，结合地热基础理论与方法，剖析了典型矿床地温特征，对温热水的补给源、热源进行了研究；结合铀成矿机理分析，探讨了热水与铀成矿作用的关系．认为相山矿田温热水属隆起断裂型热水，大气降水为温热水的主要补给源，地下水深循环及放射性生热为温热水获得热量的主要途径，热水活动对铀成矿作出了重要贡献，铀源主要来自水-岩作用，形成了受基底构造和火山盖层构造联合控制的地温高场、温热水及铀矿化于一体的空间组合．  相似文献   

大兴安岭北端阿乌尼地区中生代杂岩体的岩浆混合作用   总被引：8，自引：6，他引：8  

赵海滨  莫宣学  任院生  韩振哲  尹志刚  李尚林 《地质通报》2005,24(9):854-861

通过外野地质特征、岩相学、岩石地球化学等方面的研究，从不同的角度论证了大兴安岭阿乌尼地区出露的岩浆杂岩体在成因上具有岩浆混合作用的特点。同位素上具低的Sr初始比值和正的εNd（t）值，明显具有幔源特点，而微量元素相对富集大离子亲石元素和高场强元素又具有壳源特征，表明阿乌尼地区的岩浆岩可能是壳幔相互作用的产物。  相似文献   

Study on the Sliding Displacement of a Sliding Structure Subjected to Multi-directional Earthquake Excitation     

FanAiwu TangJiaxiang LiLi YangJun 《中国地质大学学报(英文版)》2005,16(1):79-83

The investigation of sliding isolation is mainlyfocused on the response of a structure subjected to asingle directional earthquake excitation. Fan andTang (2001) studied the slide limited friction (S LF)base isolation system, using a sequential exponentialfriction model. Zhang and Cheng (2001) studied theisolated effect of a sliding bearing as a friction damp er. Xiong and Yu (2002) studied the numerical meth od of sliding isolation system. But studying a singlecomponent of e…  相似文献   

干旱、半干旱区陆气相互作用的研究进展   总被引：5，自引：10，他引：5  

鲍艳  吕世华 《中国沙漠》2006,26(3):454-460

 对干旱、半干旱地区陆气相互作用的研究进展及发展现状做了总结，并结合近年来在干旱、半干旱地区开展的近10个有关陆气相互作用的大型野外观测试验和具有代表性的土壤水热参数化方案，分析了当前干旱区陆面过程研究中存在的问题，最后探讨了干旱区陆面过程未来的发展趋势。  相似文献   

基于B/S模式的区域水资源合理配置系统设计与开发   总被引：5，自引：0，他引：5  

钟平安  吴善锋  余丽华 《水文》2006,26(2):22-25

分析了基于C／S模式水资源配置系统的不足和B／S模式的优点;构建了基于B／S模式的区域水资源合理配置系统总体框架;阐述了ASP、COM 、WebGIS、Socket、事务处理等技术原理与应用;以 Web GIS为平台实现了空间综合信息处理、资料远程汇总、需水量计算与预测、可供水量计算、供需分析、方案评价和远程交互会商等功能。  相似文献   

橄榄岩-熔体的相互作用:岩石圈地幔组成转变的重要方式   总被引：31，自引：2，他引：31  

张宏福 《地学前缘》2006,13(2):65-75

橄榄岩-熔体/岩浆的相互作用常被用来解释蛇绿岩套橄榄岩、造山带橄榄岩、超镁铁质侵入杂岩体、地幔橄榄岩捕虏体中某些具有不平衡结构和矿物组成的岩石的形成过程。橄榄岩-熔体的反应主要有两种方式,即消耗橄榄石(和单斜辉石)生成斜方辉石或消耗斜方辉石生成橄榄石(和单斜辉石)。反应的结果不仅造成矿物百分含量的变化,而且造成矿物组成的变化;后者更重要但未引起足够的重视。华北东部中生代玄武质岩石中具有环带状结构的橄榄石和辉石捕虏晶,特别是具有环带状结构的地幔橄榄岩捕虏体的发现,暗示这种橄榄岩-熔体的相互作用在华北东南部中生代岩石圈地幔中很可能普遍存在,为岩石圈地幔组成转变和快速富集的重要方式。这是全球首例由橄榄岩-熔体相互反应造成的岩石圈地幔大规模的组成变化。反应熔体来源途径主要有地壳来源和软流圈地幔来源。来源不同的熔体与橄榄岩的反应造成的组成变化完全不同。  相似文献